Fire extinguishing system

ABSTRACT

A fire extinguishing system for extinguishing a fire on a cooking range in which a hood is mounted above the range, an elongated tubular container is mounted in the hood, a body of dry, powder-form fire extinguishing agent, containing 50 to 95 percent by weight of a metal carbonate, such as, sodium bicarbonate, 5 to 50 percent by weight of a metal silicate, such as, precipitated calcium silicate, and up to 5 percent by weight of a desiccant, such as, calcium stearate, is packed in the container between a frangible, moisture impervious disc and a free-floating piston, the disc end of the container terminates in a deflector head, adapted to direct the extinguishing agent downwardly, which carries a plurality of movable distributing nozzles, each of which is aimed at an individual burner of the range and which are provided with means for discharging the extinguishing agent in a vortical pattern, the piston end of the container is closed by a second frangible, moisture impervious disc, an actuating means, including a bottle of pressurized CO2 and a pivoted, spring-loaded arm carrying a pin to puncture the seal of the CO2 bottle, is mounted adjacent the second disc to generate sufficient pressure to fracture the second disc, drive the piston the length of the container, and pressurize the extinguishing agent sufficiently to fracture the first disc and discharge the extinguishing agent through the nozzles, a spring clip is provided to clamp the actuator arm in the cocked position with the spring under tension, and an elongated, flame-actuated sensor means, resistant to spontaneous ignition at the temperatures normally encountered in the hood, such as, a fuse wire having an aluminum core and a palladium sheath, is wrapped around the spring clip to hold it about the actuator arm, extends through an aperture in a closure cap on the container and is led across the lower lip of the hood across two burners of the range, then along the length of the hood to a point adjacent the other two burners and thence across the other two burners, whereby a flame contacting the sensor burns the sensor thereby releasing the spring clip and the actuating arm to puncture the CO2 bottle, the CO2 fractures the one disc and forces the piston through the container thereby pressurizing the extinguishing agent, and the extinguishing agent fractures the other disc and is discharged through the nozzles.

United States Patent 1 1 Dunn [ June 17, 1975 FIRE EXTINGUISHING SYSTEM [76] Inventor: Byron G. Dunn, 6831 Orchid Ln Dallas, Tex. 75230 [22] Filed: Sept. 25, [973 [21] Appl. No.: 400,623

- Related US. Application Data [63] Continuation-impart of Ser. Nos. 131,333, April 5, l97l, Pat, No. 3,773,1ll, and Ser. No, 237,515, March 23, 1972, abandoned.

[52} US. Cl. 169/59; 169/65; l69/26; 169/77; 169/33 [51] Int. Cl. A62c 35/02 [58] Field of Search 169/2 R, 26, 28, 30, 31 R, 169/33, 65, 59, 77

[56] References Cited UNITED STATES PATENTS 1,067,803 7/1913 Daniel l69/28 X 1,708,869 4/1929 Buddecke.... 169/28 2,702,599 2/1955 Sights 169/28 3,350,306 10/1967 Alleton 169/1 A X Primary Examiner-Lloyd L. King Assistant Examiner-Michael Mar Attorney, Agent, or FirmCharles F. Steininger l5 7] ABSTRACT the container between a frangible, moisture impervious disc and a free-floating piston, the disc end of the container terminates in a deflector head, adapted to direct the extinguishing agent downwardly, which carries a plurality of movable distributing nozzles, each of which is aimed at an individual burner of the range and which are provided with means for discharging the extinguishing agent in a vortical pattern, the piston end of the container is closed by a second frangible, moisture impervious disc, an actuating means, including a bottle of pressurized CO;I and a pivoted, spring-loaded arm carrying a pin to puncture the seal of the CO bottle, is mounted adjacent the second disc to generate sufficient pressure to fracture the second disc, drive the piston the length of the container, and pressurize the extinguishing agent sufficiently to fracture the first disc and discharge the extinguishing agent through the nozzles, a spring clip is provided to clamp the actuator arm in the cocked position with the spring under tension, and an elongated. flame-actuated sensor means, resistant to spontaneous ignition at the temperatures normally encountered in the hood, such as, a fuse wire having an aluminum core and a palladium sheath, is wrapped around the spring clip to hold it about the actuator arm, extends through an aperture in a closure cap on the container and is led across the lower lip of the hood across twc burners of the range, then along the length of the hood to a point adjacent the other two burners and thence across the other two burners, whereby a flame contacting the sensor burns the sensor thereby releasing the spring clip and the actuating arm to puncture the CO bottle, the CO fractures the one disc and forces the piston through the container thereby pressurizing the extinguishing agent, and the extinguishing agent fractures the other disc and is dischargec through the nozzles.

47 Claims, 23 Drawing Figures PATENTEIJJUN 17 m5 SHEEI cnhn PATENTEDJLIMY 1975 3.889754 N'IIIIII'I'I'IA FIGZ'I 1 FIRE EXTINGUISHING SYSTEM REFERENCES TO RELATED APPLICATIONS The present application is a continuation-in-part of applications Ser. No. l3l,333, filed Apr. 5, l97l now US. Pat. No. 3,773,111 and Ser. No. 237,5l5 filed Mar. 23, 1972 now abandoned by the present inventor.

BACKGROUND OF THE INVENTION The present invention relates to an automatic fire extinguishing system actuatable by a flame as opposed to heat. More particularly, the present invention relates to a fire extinguishing system, having a dry, powder-form extinguishing agent therein and suitable for use in extinguishing Class B fires, particularly as a part ofa hood over a cooking range or the like.

While a large number of fire extinguishers and fire extinguishing systems have been developed and are available on the market, numerous problems arise in connection with such fire extinguishers and fire extinguishing systems. These problems are particularly apparent in the operation of such devices, particularly for Class B fires in oils, greases, flammable liquids, etc., where blanketing or smothering by the extinguishing agent is of greatest importance.

A large number of portable fire extinguishers have been designed for extinguishing fires primarily at their inception and before the fire has a chance to develop into a large conflagration. These extinguishers have numerous drawbacks in use. First of all, they are not automatic and must be operated by hand in some fashion or another. The requirement of hand operation causes considerable delay in extinguishing the fire, to the extent that the operator is usually not familiar with the operation and usually must read the directions attached to the extinguisher before use. Also, because of unfamiliarity with the operation of the device, the operator usually completely misses the area of the fire by pointing the nozzle in the wrong direction and thereby wastes a substantial amount of the extinguishing agent as well as wasting further valuable time. In addition, such portable extinguishers are not permanently located at the area to be protected and usually, they are in the wrong place when needed.

Automatic fire extinguishing systems have also been developed, but such systems are expensive to purchase and install, they are often unsightly, and they are adapted for use where heat, rather than a flame, will actuate the device. Since these systems are actuated as a result of heat alone melting a fusible plug or link to actuate the system, such systems cannot be utilized in areas where considerable heat is normally generated. Therefore, at the present time, there has been no practical means suggested for protecting areas where considerable heat is generated and particularly, above cooking ranges.

Fire extinguishers and fire extinguishing compositions, in general, are designed for extinguishing incipient fires. Incipient fires are divided into three general groups; namely, Class A, Class B and Class C. Class A fires are those occurring in ordinary combustible material, where the quenching and cooling effects of quantities of water or solutions containing a large percentage of water are of primary importance. This, of course, is the least difficult type of fire to extinguish. Class B fires are those occurring in oils, greases, flammable liquids,

etc., where the blanketing or smothering effect of the extinguishing agent is of greatest importance. In this type of fire, liquid extinguishing materials are generally useless, particularly since they cause splattering. etc. of the liquid material which is aflame. Fires of this type are also the most difficult to extinguish since it is also necessary that the heat be cut off after the firc is initially extinguished so that the fire will not flashback or reignite in the liquid material, Hence, a fire extinguishing system for this type of fire must not only extinguish the original flame in a very short time but must have a holding capacity to maintain this condition and prevent or abate flashback or reignition. Class C fires are incipient fires of electrical equipment, where the nonconducting property of the extinguishing material is of prime importance. In this particular case, dry fire extinguishing agents are also more useful than liquid types not only because of their nonconductive properties but also because of their ability to abate reignition. In short, the same types of fire extinguishing materials as are useful for Class B fires are generally best for Class C fires because of the possibility of reignition until the condition causing the fire has been remedied.

Statistics show that approximately l4 percent of all home fires are the result of Class B fires on kitchen ranges. Such fires are also quite prevalent on Cooking units in restaurants, ship galleys, cooking units in recreational vehicles, etc. Under these conditions, one is not only faced with the inherent problems of Class B fires but the idiosyncrasies of use involved. As previously mentioned, there is the problem of the extinguishing agent causing the flaming oil or other liquid to splatter and thus spread the fire. Under these Circumstances, it is also necessary that the fire be extinguished in an extremely short period of time, particularly where a vented hood is utilized above the cooking unit. Where a vented hood is utilized over the cooking unit, there is a tendency for grease and oil to accumulate in the fan and vent and any flame on the surface of the cooking unit will rapidly pass to the vent and ignite the collected oils and greases. Also, in connection with Class B fires and cooking units, most fires start while the cooking unit is unattended, and, therefore, the heat under the cooking utensil or other item will not be turned off immediately. Consequently, even though the fire is initially extinguished, the heat under the oil or grease in the cooking utensil will flashback or reignite. One suggested solution to this problem has been to provide elaborate automatic cutoff systems for the burners of the cooking unit. However, this is, at best, an expensive and unsatisfactory solution. Accordingly, the most sim ple and inexpensive solution would be to provide a fire extinguishing system which would not only initially extinguish the flame in a very short time but would also hold this condition for an extended period of time even though the heat on the burner is not cut off. Finally, there is the problem of locating a fire extinguisher in the vicinity of the cooking unit so that it can he auto matically triggered and extinguish the fire on the cooking unit. To date, this has been virtually impossible be cause of the lack of suitable extinguishing systems and extinguishing materials which are capable of withstanding the high temperatures and moisture conditions as sociated with normal cooking over an extended period of time. Most known fire extinguishing compositions deteriorate over a period of time and must be replaced or renewed, and the problem is exaggerated by the heat and moisture to which the material is subjected during normal cooking operations.

A large number of conventional fire extinguishers are charged with liquid type fire extinguishing materials. Obviously, Class B fires cannot be extinguished with water because of the extreme danger of splattering caused by the water hitting the flaming oil or grease. The same applies to any extinguishing composition containing substantial amounts of water, such as, a calcium chloride solution. Consequently, carbon tetrachloride is one of the few known liquid extinguishing materials which is useful for extinguishing Class B and Class C fires. Carbon tetrachloride also has the advantage, over calcium chloride solutions and the conventional foam-type extinguishing materials, that it need not be renewed on a yearly basis as do the latter. While materials, such as, percloroethylene, bromoehloroethane and methyl bromide, have certain advantages over the previously mentioned liquid or foam-type extinguishing materials, these materials are rather expensive compared with the more common types of extin guishing agents. Most importantly, all known liquid type fire extinguishing materials have boiling points below about l2lC and therefore, these materials cannot be depended upon to last for any significant length of time when subjected to conventional temperatures encountered above a cooking range. While percloro ethylene does have a boiling point of l2lC, all of the other liquids or solutions mentioned have boiling points below about lOOC. Thus, the materials will evaporate quite rapidly under normal cooking range conditions, and there is no guarantee that sufficient material will remain unevaporated when the need arises. Conse quently, extinguishing materials for Class B fires, particularly on cooking ranges, are preferably the dry type fire extinguishing materials.

Most of the more common dry type fire extinguishing materials are useful in both Class B and Class C fires. This is due to the fact that these finely divided powders or dusts generally do not cause splattering of the flaming oil or grease and have a blanketing effect. While potassium aluminum fluoride and monoand diarnmonium phosphates have certain advantages over the more common types of dry chemical fire extinguishers, these materials are substantially more expensive. Therefore, the ideal and most effective materials in this catagory are the alkali metal bicarbonates and the alkaline earth metal carbonates, such as, sodium and potassium bicarbonates and calcium carbonate. The alkaline earth metal carbonates and alkali metal bicarbonates release carbon dioxide when the extin guishing material is heated by the flame of the ignited material. This carbon dioxide is, of course, heavier than air and blankets the flaming material, thus preventing access to ambient air. One drawback of dry type fire extinguishing agents is their tendency to cake or ag glomerate when subjected to moisture, even of the atmosphere, over long periods oftime. Consequently, the free flowing character of the material is reduced so that it may be diffieult to expel from the extinguisher when needed. This problem, however, has been satisfactorily solved by the addition to the dry chemical extinguish ing agent of very small amounts of desiccants; for ample, calcium stearate, magnesium stearate, talc, silica, silica gel, diatomaceous earth, calcium chloride, etc. While the dry chemical fire extinguishing agents previously mentioned, particularly the carbonates and bicarbonates, are quite effective in initially extinguishing Class B type fires, it has been found that these materials alonc lack the capacity of holding the extinguished condition and preventing or abating flashback or reignition. As previously mentioned, such flashback or reignition generally follows if the heat is not cut off beneath the cooking utensil or the like item containing the grease or oil.

Finally, in both liquid and dry extinguishing materials, there are those which release toxic gases or leave toxic residues.

lt is therefore an object of the present invention to provide a solution to the above-mentioned problems of the prior art fire extinguishing systems. Another and further object of the present invention is to provide an improved extinguishing system with a dry flre extinguishing composition. Yet another object of the present invention is to provide an improved system containing a dry fire extinguishing composition which is particularly useful in extinguishing Class B fires. Still another object of the present invention is to provide an improved system containing a dry fire extinguishing composition which is particularly useful in extinguishing Class B fires on cooking units. A further object of the present invention is to provide an improved fire extinguishing system which is relatively inexpensive. Another object of the present invention is to provide an improved fire extinguishing system containing an agent which is non-toxic and has no serious after effects when utilized for extinguishing fires on cooking units. A still further object of the present invention is to provide an improved fire extinguishing system which is capable of rapidly extinguishing a Class B fire. Another object of the present invention is to provide an improved fire extinguishing system which is highly effective in preventing or abating flashback or reignition after the fire has been initially extinguished. Another and further object of the present invention is to provide an improved fire extinguishing system which is highly effective in rapidly extinguishing the initial flame and is also highly effective in preventing or abating flashback or reignition even though the heat adjacent the ignited material is not reduced. Yet another object of the present invention is to provide an improved fire extinguishing system which is capable of withstanding varying temperatures and conditions of high humidity over extended periods of time without deterioration. These and other objects and advantages of the present invention will be apparent from the following detailed description.

SUMMARY OF THE INVENTION A fire extinguishing system to be mounted above an area to be protected, comprising; a container, a body of dry, powderform fire extinguishing agent, comprising 50 to 95 percent by weight of an alkali metal car honate, an alkaline earth metal carbonate, an alkali metal bicarbonate, or an alkaiine earth metal bicarbonate and S to 50 percent by weight of a metal silicate, disposed in the container, expelling means for expelling the extinguishing agent from the container and a flameactuated sensor resistant to spontaneous ignition at temperatures normally encountered in the area to be protected, disposed across the area to be protected and operatively connected to the expelling means to actuate the same when a flame contacts the sensor and the sensor burns. The system is preferably mounted in a hood above a cooking range and the sensor disposed across and above the burners of the range. Novel distributing nozzles are constructed to be aimed at each burner of the range and to expel the extinguishing agent in a generally vortical pattern. The extinguishing agent is preferably packed in the container between a pair of frangible. moisture impermeable discs and a freefloating piston forces the agent from the container. The actuator means includes a bottle of pressurized CO and a spring-loaded puncturing means to puncture the container and the sensor is attached to the puncturing means to hold the same in a cocked position with the spring under tension.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I of the drawings is a front view, partially in section, of the fire extinguishing system of the present invention installed in a hood over a range;

FIG. 2 of the drawings is a bottom view of the hood of FIG. 1;

FIG. 3 of the drawings is an exploded view of the cannister assembly and nozzle assembly of the system of FIG. 1;

FIG. 4 is a side view, partially in section, of the cannister;

FIG. 5 is an end view of the cannister of FIG. 4;

FIG. 6 is a bottom view of the cannister of FIG. 4;

FIG. 7 is a side view, partially in section and partially exploded of the end cap assembly of the cannister;

FIG. 8 is an end view of the actuator plate;

FIG. 9 is a sectional view taken along the line 9-9 of FIG. 8;

FIG. 10 is a sectional view taken along the line l0l0 of FIG. 8;

FIG. II is a side, cross-sectional view of the piston assembly;

FIG. 12 is a side view of the actuator bracket and actuator assembly;

FIG. 13 is an end view ofthe actuator bracket and actuator assembly of FIG. 12;

FIG. 14 is a top view of the spring clip of FIGS. 12 and 13;

FIG. 15 is a bottom view of the hammer bracket of FIGS. 12 and 13;

FIG. 16 is an end view of the hammer bracket of FIG. 15;

FIG. 17 is a side view of the hammer bracket of FIG. 15;

FIG. 18 is an end view of the nozzle base;

FIG. 19 is a side view, partially in section, of the nozzle base of FIG. 18;

FIG. 20 is an end view of the nozzle base of FIG. 19;

FIG. 21 is a side, cross-sectional view of the assembled nozzle assembly;

FIG. 22 is a top view of the distributing nozzle of FIG. 21; and

FIG. 23 is a cross-sectional view taken along the lines 23-23 of FIG. 22.

DETAILED DESCRIPTION OF THE INVENTION In accordance with FIGS. 1 and 2 of the drawings, numeral 10 refers to a cooking range of conventional construction having top burners 12. While only two burners are shown, it is to be understood that the stove will normally have four such top burners. Mounted anywhere from 20 to inches above the range surface (standard installation) is a hood l4. Mounted under the hood [4 by means of mounting bracket 16 is fire extinguishing cannister assembly 18 equipped with nozzle assembly 20 having distributing nozzles 22. Leading from the rear of cannister assembly 18 is sensor 24. Sensor 24 is led through eyelets in mounting brackets 26 to a terminal ring-type bracket 26' to cover the surface area above the burners. Mounting bracket 16 is affixed to the bottom of hood 14 by means of double backed adhesive (not shown) or other appropriate mounting means. Normally, prior to installation, each of the nozzles 22 is rotatable throughout the entire area of a circle perpendicular to the nozzles so that they may be aimed at each individual burner. Each individual nozzle 22 is aimed at an individual burner 12. After the aiming has been accomplished, the nozzles are sealed to the nozzle cap so they will not he accidentally moved out of alignment, the canister is sealed to the bracket and the nozzle cap is sealed to the canister. To the extent that the hood I4 is provided with a filter 28, the sensor 24 is led over the mounting brackets 26-26 about the exterior of three sides ofthe filter. The sensor should not cross underneath the filter since this will interfere with removal and cleaning of the filter. If the hood does not have a filter, then sensor 24 is mounted so as to cross over all of the four burners of the range 10.

FIG. 3 of the drawings shows an exploded view of the canister assembly 18 and the nozzle assembly 20 ofthe fire extinguishing system of the present application. In FIG. 3, a main tubular body portion 30 is provided. Body portion 30 is threaded at its rear end portion 32. Mounted inside tubular body 30, adjacent the front end thereof and resting against a reduced shoulder (hereinafter referred to), is frangible disc 34. The tubular body 30 is packed with a dry chemical fire extinguishing agent 36 (hereinafter referred to in greater detail). Thereafter, a piston assembly 38 is positioned in tubular body 30. The rear end of tubular body portion 30 is then closed by means of frangible disc 40 mounted on actuator plate 42. Actuator plate 42 has mounted thereon actuator assembly 44. Actuator plate 42 rests on a shoulder (hereinafter referred to) in end cap assembly 46. Cap 46 is screwed on portion 32 of tubular body 30 and sealed by means of O-ring 48. The front end of tubular body 30 is closed by an integrallyformed, deflector head portion 50. Head portion 50 directs the extinguishing material 36 downwardly where it exits through mounting head 52. Mounted within an annular groove in mounting head 52 is O-ring 56 which forms a part of nozzle assembly 22. Nozzle assembly 22 includes nozzle base 58 which mounts on mounting head 52. Nozzle base 58 has hemispherical nozzle supports 60 provided with angularIy-disposed apertures 62. Passing through apertures 62 are distributing nozzles 64. Distributing nozzles 64 have mounted in their upper ends nozzle deflectors 66 and in their lower ends temporary nozzle seals 68. The free ends of distributing nozzles 64, which pass through apertures 62, have slidably mounted on the outside thereof nozzle retainers 70. Nozzle retainers 70 are press-fit on nozzles 64 in a manner such that nozzles 64 and nozzle retainers 70 are freely movable over a wide angular range about hemispherical supports 60.

FIGS. 4, 5 and 6 show. in greater detail, the main body portion 30, the head portion 50 and nozzle assem' bly mounting head 52 of canister assembly I8. As is evident from FIG. 4, body portion 30 is provided at its forward end with inner, annular flange or shoulder 72 on which frangible disc 34 of FIG. 3 is sealably mounted. Nozzle assembly mounting head 52 is provided with annular groove 54 and. as shown in FIG. 6, with outwardly projecting flange elements 74. Flange elements 74 cooperate with corresponding inner flange portions of nozzle base 58 to form a bayonettc means to lock the nozzle base 58 on the mounting head 52.

FIG. 7 of the drawings shows, in cross-section, end cap assembly 46. In accordance with FIG. 7, end cap assembly 46 is provided with shoulder 78 adapted to receive ()-ring 48 (FIG. 3) and shoulder 80 adapted to receive actuator plate 42 (FIG 3 End cap 46 is inter nally threaded at section 82 so to threadedly mount on threaded portion 32 of body 30. End cap 46 is provided with a centrally-disposed aperture 83 and an offset post or boss 84. Sensor wire 86 passes through aperture 83 and is connected to or forms a part of sensor wire 24 of FIG, 2 of the drawings, When gas pressure is generated behind the piston 38 (FIG. 3) and frangible disc 40 (FIG. 3) is fractured thereby, the aperture 82 through which sensor 86 passes is closed by means of a flapper valve or flexible disc 88 of neoprene or the like which is mounted on post 84. Flexible disc 88 is held in place by means of plastic washer 90 which, in

turn. is held in place by means of push-on lock ring 92.

FIGS 8, 9 and show the detail of actuator support plate 42. Actuator support plate 42 is provided with central aperture 94. Central aperture 94 provides a passage through support plate 42 when gas pressure behind the support plate ruptures frangible disc 40 (FIG. 3). Actuator support plate 42 is provided with generally rectangular upstanding post or boss 96 and elongated upstanding post or boss 98. Posts 96 and 98 are adapted to receive therebetween a pressurized gas bottle, hereinafter referred to. which is part of the actu ating mechanism. Upstanding post 96 is provided with protruding cylindrical posts or bosses 100 which are adapted to receive an actuator bracket, hereinafter described with respect to FIGS. 12 and 13. Post 96 is also provided with aperture 102 in which a screw (hereinafter referred to) is mounted to hold the actuator bracket in place. Actuator plate 42 is also provided with upstanding posts or bosses 104, which serves as a support for the neck of the gas bottle, and 106, which serves as a stop for the end of the gas bottle. Plate 42 is also pro vided with post or boss 108 having a central bore 110. The central bore 110 is adapted to receive the pivot post for the actuator assembly (hereinafter referred to in FIG. 12). Upstanding post or boss 112 is formed on actuator plate 42 and extends across aperture 94. Post 112 is also provided with a central bore 114 adapted to receive one end of the clip (hereinafter mentioned with respect to FIG. 12) of the actuator assembly. Finally, the actuator plate 42 is provided with an upstanding post or boss 116 which is adapted to hold one end of the power spring (hereinafter referred to in FIG. 12) of the actuator assembly.

FIG, 11 of the drawings shows piston assembly 38 in detail, Piston assembly 38 is made up of main piston body 118 and piston insert 121). Piston insert 120 has a slightly larger diameter than piston 118 and thereby forms the main seal against the walls of tubular body member (FIG. 3). By this means. the friction of the piston being driven through body 30 can be reduced over that which would exist if the entire cylindrical portion of piston assembly 38 were made exactly the same diameter.

FIGS. 12 and 13 show the actuator assembly 44 in detail. Actuator assembly 44 is held in place by actuator bracket 122. Actuator bracket 122 is provided with a flange portion 124 which extends over and holds pressurized gas bottle 126 in place. As previously indicated, with respect to FIGS. 8 through 10, gas bottle 126 is received between posts 96 and 98 of actuator plate 42. The neck of pressurized bottle 126 rests on post 104 of actuator plate 42 and the end of the neck fits against stop post 106. Actuator bracket 122 is provided with apertures 128 which fit on posts ofactu ator plate 42. Passing through a central aperture between posts 28 is a screw 130 which passes into aperture 102 of plate 42 to hold actuator bracket 122 in place. Actuator bracket 122 is provided with an aperture 132 which cooperates with aperture 110 in plate 42 to receive pivot pin 134 of the actuator assemblyv Mounted on pivot pin 134 is hammer bracket 136. Hammer bracket 136 carries hammer 138 with puncturing pin 140. The puncturing pin 140 is so aligned that it will puncture the seal of gas bottle 126 at an appropriate time. Hammer 138 is manufactured as a separate entity from hammer bracket 136 and is attached thereto by swaging a central post 142. Pivot pin 134 also carries helical, power spring 144 which has one end thereof resting on top of hammer bracket 136 and the other end thereof resting against post 116 of support plate 42. The solid line outline of hammer bracket 136, hammer 138 and spring 144 show the active or re leased position of these elements. Shown in dashed lines is the cocked or inactive position of hammer bracket 136, hammer 138 and spring 144. Hammer bracket 136 is held in the cocked position by means of clip 146. Clip 146 is held in place by having two side extensions thereof pass into aperture 148 in the actuator bracket 122 and aperture 114 of plate 42. Clip 146 is therefore free to rotate or pivot to a limited extent making it possible to align the clip with hammer bracket 136. However, bracket 136 is thereby held in the cocked position by gripping the same between the legs of clip 146 and then wrapping sensor 86 about the free ends of the clip. Thus, it is obvious that the actuator, once cocked, will operate as follows: The sensor 86 will burn. releasing the tension on clip 146. Clip 146 will thereby release hammer bracket 136 which is driven by power spring 144. in the extreme, hammer bracket 136 will assume the position shown in solid lines with the hammer 138 against the end of gas bottle 126 and the puncturing pin 140 through the seal of gas bottle 126.

FIG. 14 of the drawings shows a detailed top view of clip 146.

FIGS. 15, 16 and 17 show bottom, end and side views, respectively, of hammer bracket 136.

FIGS, 18, 19 and 20 of the drawings show top, side and bottom views, respectively, of the nozzle base 58 (FIG. 3). Obviously, internal flanges 76 of base 58 are designed to cooperate and lock in a bayonette-type connection with external flanges 74 of mounting head 52 (FIG. 6),

FIG. 21 of the drawings shows the nozzle assembly 22 (FIG. 3) in its assembled condition. The assembly, of course, includes nozzle base 58 having hemispherical projections 60 with apertures 62 formed therein. Pass ing into and through the apertures 62 is distributing nozzle 64. Distributing nozzle 64 has temporary end cap 68 mounted in one end thereof and nozzle defleo tor 66 mounted in the opposite end. Distributing nozzle 64 is also provided at its upper end with angularly disposed apertures l50. When pressure is applied to the dry extinguishing agent 36 (FlG. 3) in body 30 of the canister assembly, the pressurized extinguishing pow der is forced outwardly through apertures 150 and the interior of nozzle 64 and this pressure blows cap 68 out the end of nozzle 64. Otherwise, cap 68 provides a seal to prevent grease moisture and the like from entering the nozzle assembly. Apertures 150 also serve a very distinct purpose. As will be seen from FIGS. 22 and 23, apertures 150 are disposed parallel to the radii of nozzle 64 and offset therefrom. By this placement, the powdered fire extinguishing agent exits through nozzle 64 in a swirling or a vortical motion due to the coaction of and placement of the apertures 150 with respect to deflector 66. This has a critical effect on the distribution of the powdered extinguishing agent over the area to be protected.

The canister assembly and the nozzle assembly are preferably made of a material having a high degree of toughness, impact strength, heat resistance and dimensional stability and good electrical properties. While there are a number of metallic or plastic and resinous materials which can be utilized, the preferred material is Lexan 101 manufactured by the General Electric Company. This material is a thermoplastic polycarbonate resin suitable for use in molded or extruded structures and exhibits all of the properties specified above. Any parts of the device which are metallic are preferably zincor cadmium-plated ferrous parts or stainless steel. Where parts of the system are to be bonded together, such as, the nozzle retainer to the distributing nozzle, the piston insert to the piston, the nozzle base to the canister assembly, the canister to the canister support, etc., this can be accomplished by the use of a suitable solvent for the Lexan, such as, ethylene dichloride.

The sensor should be selected on the basis of the conditions to which it is subjected. The primary requisite is that the sensor should not be spontaneously ignited by heat alone but will be ignited and burn rapidly when a flame strikes it. The sensor may take the form of an organic filament, such as, cotton, rayon, silk, etc. or a synthetic filament, such as, nylon (linear polyamide), orlon (linear polyester), dacron (linear polyacrylonitrile), etc. Under certain circumstances, however, and, particularly, for use in the hood of a cooking range or the like, such organic filaments will not ignite or burn rapidly enough to satisfy the needs of the system. Accordingly, the sensor is preferably a fuse material, such as, cordite or a wire-type fuse. A desirable sensor wire is one having a minor proportion of a noble metal and a major proportion of aluminum. A particularly pre ferred material is a wire-type fuse known as PYRO- FUZE manufactured by Pyrofuze Co. of Mount Vernon, New York. This sensor wire is a coaxially braided material having an aluminum core and a palladium shell. Platinum may also be used as the shell material. The wire is preferably 0.004 inch diameter and withstands a breaking load of about 9 pounds. The wire normally will not ignite or burn at radiant heat temperatures as high as l200F but will ignite instantaneously and burn rapidly, at a rate of about 0.9 foot per second, when contacted by a flame.

The frangible discs utilized in accordance with the present invention are a laminate of paper-polyethylenealuminum foil-polyvinyl. They should have a rupturing strength of near or below 15 pounds per square inch and a thickness of about 0.005 inch.

The nozzle seals are preferably of molded plastic lined with a laminate of paper and aluminum foil.

The pressurized gas bottle is preferably a bottle containing about 8 g. of liquifled CO and (as appears in the test data hereinafter) develops an average pressure of about 46 pounds per square inch during discharge of the extinguishing agent. ln actual practice, the gas ruptures frangible disc 40 (FIG. 3] and pressurizes the extinguishing agent 36 (FIG. 3) which, in turn, ruptures frangible disc 34 (FIG. 3). A suitable CO cartridge is the type manufactured for Mae West life jackets. This component is designated by the US. Military as MlL-C-601B, Type I.

The power spring 144 (FIGS. 12 and 13) provides a torque, when cocked, of about 3.75 inch per pound.

A critical component of the system of the present application is the dry, chemical fire extinguishing agent. Such an extinguishing agent must meet a number of very stringent requirements. First of all, it must be capable of extinguishing a Class B lire, which is a fire occurring in oils, greases, flammable liquids, etc. ln extinguishing such fires, it is necessary that the extinguishing agent have a blanketing or smothering effect. C0nse quently, liquid fire extinguishing materials are gener ally useless, particularly, since they cause splattering, etc, of the liquid material which is aflame. Class B fires are also the most difficult to extinguish since it is also necessary that the heat be cut off after the fire is initially extinguished so that the fire will not flash back or reignite in the liquid material. Hence. The fire extinguishing material for this type of tire must, not only, rapidly extinguish the original flame but hold this condition and prevent or abate flashback or reignition even if the burner of the range is left on. The fire extinguishing agent of the present system meets and exceeds all of these requirements. The tire extinguishing agent of the present invention is a synergistic mixture of about 50 to 95 percent by weight of an alkali metal carbonate, an alkaline earth metal carbonate, an alkali metal bicarbonate or an alkaline earth metal bicarbonate and about 50 to 5 percent by weight of a metal silicate. Be cause of its availability, effectiveness and freedom from toxicity, the preferred carbonate is sodium bicarbonate. Preferably, the sodium bicarbonate is present in amounts between about 85 and 60 percent by weight of the composition. Specifically, the most desirable composition contains about 78 to 80 percent by weight of sodium bicarbonate. The metal silicate is preferably a nontoxic alkali metal or alkaline earth metal silicate and of a substantially pure character, such as, a material manufactured by precipitation. A highly effective silicate for use in accordance with the present invention is "Silene L", manufactured by Pittsburgh Plate Glass Company, Pittsburgh, Pennsylvania. This mate rial is a precipitated calcium silicate and has an approximate analysis of CaO l9 percent and SiO 57 percent; and a loss on ignition of about 14 percent. It has a specific gravity of about 2.1 and bulk density of about 15 to 16 pounds per cubic foot. The preferred range of sili' cate is in the amount of 15 to 40 percent by weight and, specifically, the most effective has been found to be about l9 to 20 percent by weight. The composition may also include minor amounts of, up to about 5 percent by weight of conventional desiccants, lubricants,

adsorbents and the like. Suitable materials of this character include calcium chloride, diatomaceous earth. silica gel. calcium stearate. etc. and preferably are present in an amount of about 3 percent. Calcium stearate of the extinguishing agent and nearly 400 tests were carried out by application of the extinguishing agent from the extinguisher system. The testing was carried out, in most cases, utilizing an off-the-shelf gas cooking is a preferred desiccant. However, this last component 5 surface. is not necessary to the synergistic effect of the mixture Various vessel sizes and materials were tested includof the present invention nor to its free-flowing propering cast aluminum. sheet aluminum. cast iron, sheet ties. It has been found in accordance with the present steel and teflon coated cooking utensils. A ten inch diinvention that the mixture of bicarbonate and silicate ameter stamped sheet steel skillet was found to be the has free-flowing characteristics making its discharge most problematical and was selected for most of the from a suitable extinguishing apparatus superior to tests. most conventional extinguishing agents. It also resists V i Common consume; fl bl were tested stratification in storage and in the extinguishing appai l di Com il vegetable shgrtgning heavy d ratus. The mixture is also capable of withstanding ex peanut oil, animal fat (bacon grease), used restaurant treme temperatures WllllOUt deterioration, thereby progrease and safflower i] with and withgut foods in (h viding long shelf life and useful life without recharging 1L Heavy d t peanut il demonstrated h greatest or replacement and is relatively resistant to moisture tendency to reignite and was used in most of the tests, data-oration The h h m fire FXhhguiSh-mg The burners of the range were all rated for BTU outagent f the present lhvhhhoh packed m body of put. It was found that the greatest difficulty in preventthe canister between frangible discs 34 and 40 by vibraing reignit-lon was encountered when using a 02 BTU tion of the canister and is the only known dry, chemical burner fixungulshmg agent which 'f P m this The chemical extinguishing compositions were tested Thls packmg of h elfhhgulshmg agent has i for their ease and completeness of discharge from the approvyed by uhderwmhrs Laboratonhs h 35 extinguishing unit, their tendency to cause splashing or hated P material approved forpackmg [hls splattering of liquid oils and greases, their ability to h Thlsi of l C0hmbhtes to I quickly extinguish a flame, their ability to prevent stratification. The frangible discs not only maintalhthe reignition for at least 10 minutes and their ability to body of dry hre hxhhgulshmg Chemlca] the Comalher withstand prolonged extremes of heat and cold without until it is to be discharged and prevent the material deterioration from phlggihg the h l System or fouhhg mg .acmator The best commercially available dry chemical fire exmechamsm but mahham rholsture bamer whlch helps tinguisliing compositions were tested as well as various to prawn the exhhgmshmg agent from absorbmg combinations of the ingredients of these compositions. water or grease hh from atmosphere under The following Table 1 shows the results of the testing most adverse cohdlhohs' of these commercially available materials. In the fol- A The System of the presehi lhvehhoh has been lowing table. some of the tests, which were conducted Jected to numerous demahdmg 1 by the manufac for the purpose of determining the reignition properties turer and Underwriters Laboratories and has been apof the extinguishing agent were conducted by hand Prhved by Uhdsrwlhers Laboratories for Class B plication of the extinguishing composition. In this case, and given a 4 year shelf life without replacement. This 40 the malaria] was hand shaken from a perforated {Wm Shelf hfe differs radically from that extended to any quart saucepan. In the remaining tests, the extinguish other System of this Character Oh the market Since ing composition was discharged from the extinguishing other available units of this character have a one year System T i l f d to below as Super i rating at mosh The System is rated for the Protection Of a material of unknown composition developed by the the maximum horizontal area Of about 7 square feet Navy fer purpose Compositien number 4 is a with a maximum dimension Of 42 inches at h ig ts nycommercially available extinguishing material, whereas where between 20 and 3 in h abOVfi h PfOteCtcd composition number 5 represented a mixture of 90 percooking surface. The unit is also rated to ithstand amcent of this commercially available material mixed with bient temperatures between 32 and l00F Tests nd 10 percent calcium silicate. ln rating the completeness cate that the system is capable of extinguishing agrease of discharge from the extinguisher. it was considered fire in less than about 5 seconds and preventing reignithat discharge of less than about 85 percent of the tion for at least 10 minutes. However, the data which chemical fire extinguishing composition from the appafollows clearly indicates that, in most cases, the system ratus was a failure, while discharge of more than this far exceeded these minimal requirements. amount was considered to pass the test. A passing ratln developing the system of the present invention. a ing for rcignition was based on prevention of reignition number of tests were carried out by hand applic i for at least 10 minutes with the range burner still on.

TABLE 1 it by wt. Test Chemical Type of Manner of Fire Extin- Scries Composition Test Application guishment Reignrtion Discharge Remarks l KHCQ, Chemical Canister Pass Fail Fail Tendency to "cake" I NaHCO System Canister 4 Pass U i all 2 Pass: Fail 4 Pass l (ius release incomplete Relgnition Hand 4 Ptihh Y i-inl Z luss l l-iul Z Boil-overs contributed to reignition TABLE 1 -Cntinued (k by Wt.) Test Chemical Type of Manner of Fire Extin- Series Composition Test Application guishment Reignition Discharge Remarks 3 Casio Reignition Hand Pass Fail 4 87KHCO System Canister Fail Fail Chemical block lUCdSiQ, in extinguisher 3 Silica Gel 5 78,3 KHCQ, System Canister Fail Fail Gas channeled l9,() CaSiO through chemical Z7 Silica Gel and noz/lcs plugged 6 67.5 KHCQ, System Canister 2 Fail 2 Pass Chemical too 20.0 NaHCO widely dispersed I01) CaSiO 2.5 Silica Gel 7 57 KHCO System Canister 2 Fail 2 Pass NaHCO 10 CaSiO 3 Silica Gel K 80 NaHCO, Chemical Hand Fail 2t) CaCO;,

9 70 NaHCO Reignition Hand 3 Pass 1 Puss-2 Fail 2 Boil-overs 3U Na BHOJ, contributed to reignition IO NaHCQ, System Canister Pass Fail Pass Some chemical compacted 5U N WPOQ Reignition Hand Fail ll NaHCO Reignition Hand 2 Pass 1 Pass-l Fail 2 Pass 40 Na B(P(L) System Canister 5 Pass l Pass-4 Fail 4 Passl BoiLover l Fail contributed to reignition 12 72 NaHCO Rcignition Hand Fail l8 CaSiO l0 Na BIPOJ i3 NaHCO Reignition Hand Pass Fail Boil over con- 10 CaSiO tributed to relO Na B(PO ignition l4 NaHCQ Reignition Hand Pass Fail Boil-over con 5 CaSiO tributed to re- 5 Na BtPofl ignition l5 "Super K Discharge Canister 9 Pass- Piston stopped 8 Fail in several runs System Canister 4 Fail 3 Passl Fail The results of the series of tests set forth in Table l 45 with a metal silicate, such as, calcium silicate, promake it obvious that the compositions tested had an duced a synergistic effect and that this combination mordmently large number of failures in one respect or was highly successful in extinguishing Class B fires another and therefore, are not suitable for a reliable exwhen used in the system of the present invention. The tmguishtng system of this character. following Table 2 sets forth the results of a series of It was then surprisingly discovered that a mixture of 50 tests conducted with sodium bicarbonate alone and ca]- sodlum bicarbonate or other alkali metal or alkaline cium silicate alone as well as various mixtures of these earth metal carbonates or bicarbonates in combination two materials.

TABLE 2 Chemical Test Composition Type of Manner of Fire Extin Series (7r by Wt.) Test Application guishment Reignition Discharge Remarks l NaHCQ, System Canister 4 Pass-U Fail 2 Pass-2 Fail 4 Pass 1 Gas release incomplete Reignition Hand 4 Pass-2 Fail 2 Pass-2 Fail 2 Boil-overs contributed to reignition 2 NaHCO System Canister Pass Fail Pass Considerable splatter 5 Casio Reignition Hand 2 Pass 2 Pass 3 )ONaHCO System C anistcr 4 Pass 3 Pass-l Fail 4 Pass lUCaSiO; Reignition Hand l4 Pass 8 Pass-6 Fail l4 Pass 3 Boil-overs contributed to reignition TABLE 2 -C ontinued Chemical Test Composition Type of Manner of fire EXHIF SClltf (92 by Wt l Test Application guishment Reignititm Discharge Remarks 4 h5NaHCU Reignitiun Hand ll Pass-1 Fail 7 Pass-4 Fall A l5faSiU System Canister 4 Pass 7 Pass-2 [ail 8 Pasl Fail 5 tiUNaHfIL Relguition Hand 3 Pass 2 Pass-l Fail (11510 5 stem 45 Passl Fail 3i) Pass-l l Fail 3H Pass 4 lncunclusi\c H lail reigmtiuns due 4 inconclusne to putting burner out 2 Reignition fai lures due to poor placement of chemical l Discharge fai lure due to gas channeling 3 Discharge failures due to equipment failure ti 75NaHCU System ('anistcr 2 Pass-l Fail 2 Faii Z Patsy l Rcignitiun Z5CaSiQ; l Fail failure and 1 ex tinguishmcnt fab lure due to poor placement of chemical l Reignitiun failure l Discharge failure due to gas discharge incomplete 7 JONaHfQ System Canister Pass Fail Pass ZOCaSiO; Reignition Hand 2 Pass l Pass l Fail i 8 fitlNaHCO System Canister 3 Pass 3 Fail 3 Pass 4 4(JCaSiQ Reignition Hand 1 Pa." 1 Fail 1 Pass A i 9 5Ol\laHCO System Canister 5 Pass l Fail I Pass-4 Fail 6 Pass 1 Extinguishmcnt SUNaHCO failure and 2 reignition failures due to poor placement of chemical Reignitiun Hand Pass Pass Pass It) iztSiO; Reignition Hand Pass Fail It is apparent from the above that a composition containing from about 95 to 50 percent by weight of sodium bicarbonate and from about 5 to 50 percent by weight of calcium silicate was highly effective for the purposes indicated. Where less than 5 percent calcium silicate or no calcium silicate was used, it is obvious that the results are little better than those with the previously tested materials of Table 1. Likewise, a large' number of failures were found to occur, particularly on the tendency to reignite, when 50 percent of sodium bicarbonate is mixed with 50 percent of calcium sili cate. It is also significant that at less than about 15 percent calcium silicate, and at more than about 40 per cent calcium silicate, the results were relatively poor compared with compositions contaiing between about 15 and 40 percent of calcium silicate. Consequently, the preferred compositions in accordance with the present invention contain about 85 to 60 percent so dium bicarbonate and 15 to 40 percent of calcium silicate. These ranges were also applicable to use of other alkali metal and alkaline earth metal carbonates and bicarbonates and other metal silicates.

While it is not intended to be limited to any specific theory of the effectiveness of the composition. it is believed that the ability of this composition to prevent reignition is due to the formation of a hard, air impermeable crust on top of the flammable liquid, thereby preventing air from reaching the flammable material which would cause auto-ignition. This is particularly significant since in many of the tests, a six-channel tem perature recorder was employed having sensors in the oil, at the nozzle of the extinguisher, at the actuator of the extinguisher (gas bottle), between the heat shield of the extinguisher and the extinguisher, at the hood filter and at room temperature As a result of checking these temperatures, it was found that the temperature in the oil after extinguishment of the initial fire and with the range burner still on was substantiaily higher than the initial autoignition temperature of the oil (as high as 600C).

It was also determined that the most effective compo sition was one containing 78 to 80 percent sodium bicarbonate and 19 to 20 percent of calcium silicate. The effectiveness of this composition is best illustrated by a series of tests carried out to establish compliance with the standards of Underwriters Laboratories, lnc, for the classification, rating and tire testing of Class B-l fire extinguishers. Some of the more significant criteria set forth in these performance specifications include, fire tests utilizing a square steel pan 8 inches in depth made from '16 inch thick steel, 2% feet square, having 2 inch layer of oil or n-heptane and partially filled with water, if necessary, to reach a height of about 6 inches plus or minus 5 4 inch below the top edge of the pan. The extinguisher is to be located 24, 28 and 30 inches above the oil surface. The sensors and actuation system must be capable of discharging dry chemical within a maximum of 5 seconds. The tests must also be conducted so that the chemical will be discharged over an area 40 inches by 30 inches (the largest standard range forth the results of a series of tests carried out to meet 10 the Underwriters specifications. In some runs in this series of tests, the extinguisher was preconditioned by storage for the specified period of time at either 32F or 120F. It should also be noted that in tests 4 and 7, which are the most severe. the sensor wire, the extinguisher and the inside of the hood were coated with used grease prior to the test in order to determine whether the grease would be ignited at any time during the course of the test. In tests l through 22, the unit was charged with 800 g. of extinguishing agent and in the tests 23 through 25. production models were charged with 950 g. of extinguishing agent.

TABLE 3 Type Nozzle Test of Conditioning Height Test Test Time in Sec. Reignition- Delivery No. Test Test & Time (lt'L) Vessel Fuel Actuation Extinguish Test Time or Splash l Extin- 32 30 Dutch oven 84in. 37.6 45.5 Pass Pass guish 20 hrs. (ll X 7 in} geanut l7 min.

il Extin- 32 30 Cast iron 0.31m. guish 2l hrs. skillet Peanut (l3 /4 Oil (l lb.) 63.0 700 Pass Pass X 2 in] 29 min. 3 Extin- 32 30 Steel 0.35 in. 43.0 45.8 Pass Pass guish 22 hrs. Skillet Peanut 22 min.

(IOX2in.) OiIU/fi lb.) 4 Extin 32 30 Steel pan 0.40 in. 25.0 29.0 Pass Pass guish l4 hrs. (24 X 30 X Peanut 75 min.

3 in.) Oil (4.4

lb.) 5 Extin 32 30 Steel 040 in. 28.6 33.7 Pass Pass guish l6 hrs. Skillet Vegetable 63 min.

(l 2in.) Oiltl lb.) 6 Extin- 32 30 Steel 0.40 in. 4L6 45.) Pass Pass guish 6 hrs. Skillet Corn Oil 22 min.

(l0X2in.) (%lb.) 7 Extin- 32 30 Steel 9 strips 33.3 36.5 Pass Pass guish 7 hrs. Skillet bacon 24 min.

(1(1X2in.) 0.32m.

grease 8 Splash I20 20 Cast lron 0.25 in. 49.8 SL8 Pass Pass 8 hrs. Skillet Peanut 20 min.

(6X1 in.) Oil(50g.) 9 Splash l20 20 Steel pan 0.40 in. 26.8 29.2 Pass Pass [9 hrs. (24 X 30 X Peanut Oil 86 min.

3 in.) (4.4 lb.) 10 Splash 120 20 Cast lron 0.25 in. 46.3 49.6 Pass Pass 15 hrs. Skillet Peanut Oil l7 min.

a t 50 g.) in.) l l Splash 120 20 Dutch Oven Mn. l H) 17.6 Pass Pass 17 hrs. (l l X 7 Peanut Oil 24 min.

in.) 12 Extin- 32 30 Dutch Oven Vu'n. 33.6 4l.0 Pass Pass guish ll hrs. ll X 7 Peanut Oil l8 min.

in.) l3 Extin- 86 24 Steel Skil- Peanut Oil 34.0 35.2 Pass Pass guish let l0 X (0.7 lb.) l6 min.

2 in.) l4 Extin- 80 24 Steel Skil- Peanut Oil 460 47.1 Pass Pass guish let (l0 X (0.7 lb.) l6 min.

2 min.) Extin- 86 24 Steel Skil- Peanut Oil 4L0 42.2 Pass Pass guish let H) X (0.7 lb.) l4 min.

2 in.) If) Extin- 87 24 Steel Skil Peanut Oil 42.0 43.1 Pass Pass guish let X (0.7 lb.) 15 min.

2 in.) l7 Extin- 8l 24 Steel Skil- Peanut Oil 62.0 63.2 Pass Pass guish let l0 X (0.8 lb.) 16 min.

2 in.) 18 Extin- 79 24 Steel Seven 37.0 38. Pass Pass guish Skillet strips 20 min.

(l0 X 2 bacon in.) I; Extin- 79 24 Cast Iron l5 strips 47.0 48.3 Pass Pass guish Skillet bacon 20 min.

(l3 A X (0.38 in. 2 in.) grease) 20 Extin- 65 24 Steel Pan 0.28 in. 28.0 29.2 Pass Pass guish (24 X X Peanut Oil 43 min.

3 in.) (4.4 lb.)

TABLE 3 --Continued Type Nozzle Test of Conditioning Height Test Test Time in Sec. Rcignition- Delivery No. Test Test 8! Time (In) Vessel Fuel Actuation Extinguish Test Time or Splash 21 Extin- 65 24 Steel 0.40 in. 36.0 37.l Pass Pass guish Skillet Corn ()il min.

(10x2 (/zlbl in.i 22 Extin 74 24 Steel Salllower 48.0 490 R155 Pass guish Skillet Oil 13 minv X 2 lb.) in.) 23 Splash I2U Cast Iron 0.20 in. Pew No Skillet nut Oil Splash 16 X l in l g.) 24 Extin- 32 30 Steel Pun 0.25 in. 15.8 17.0 Pass Pass guish (42 X 24 X Peanut Oil 20 min.

3 in.) (2800 g.) 25 Extin- 32 20 Steel Pan 0.25 in. lfifi 20.0 Pass Pass guish (42 X 24 X Peanut Oil l0 min.

3 in.) (2800 g.)

Tests were also conducted to determine the actual pressure developed in the canister and the amount of chemical discharged. The results of these tests are set forth in Table 4 below. Except where indicated, the pressure was measured by a pressure transducer and recorded by a chart recorder.

TABLE 4 average yield strength (considered to be the first significant deflection of the load-deformation curve) averaged 1 I24 pounds.

Sections of the canister were also exposed to ultraviolet light from two single enclosed carbon arc lamps. Water was automatically sprayed into the specimen at PROTOTYPE UNITS Conditioning Maximum Dry Chemical Dry Chemical (ollectcd Temperature, Pressure Discharged. From Nozzle. G

Degrees F PSIG Ci Per Cent l 2 3 4 32 737 (921] 200 I70 I73 2l6 70 IIO*** 72 (9|.3) 215 I I27* l9l 120 100*" 712 (89.0) I69 I80 I83 206 PRODUCTION L'NITS 32 80* 874 (92.0) 212 227 ..4l I95 70 844 (88.8] I92 236 27 I90 I20 90* 889 (93.6) 202 23l 229 222 70 58 893 (94.0) 70 38 719 (75.7) 70 47 7l9(75.7l 7U 39 794 (83.6) 70 52 868 (91.4) 70 43 794(8311) Avg.=46 70* 86 893 (94.0) 70 69 889 (93.6) I20"* 36 753 (79.2) l20** 88 9l3(96.l| I20 2 0I6t9(1.2 (24 Hrs.) ilh.)

70 (24 Hrs.) 2,023 (96.6)

(lhi

Some dr chemIcul spilled from bug. Two frangible discs al each location 'Preswre measured using pressure gauge (II-I000 psi) In addition to the test results given above, the y tem predetermined intervals. The arc was formed between was subjected to a number of other rather stringent 011C pp electrode and lower, Veftmal elfictmdes tests. held in a solenoid-actuated speed mechanism. All elec The body of the unit was subjected to air-oven aging tr w r f r n. 1/2 inch in diameter, the pp for 17 days at 212F and 75 days at 2l2F. After the ,0 electrode being of the SOlld type and the lower elecaging period, the units were examined for cracking, pittrOdfiS belng 0f the fleull'al- Cored yp Vice Vfifsa, ting, deformation and other signs of deterioration. The potential across the arc was 120 to 145 volts AC Rings l in. wide) were also cut from several aged sanr a an p r ing Current of about 15 to 17 p water, ples and subjected to a crush test. A crosshead speed at room temperature, was sprayed horizontally onto the of 0.5 inch per minute was used in an Instron Testing samples at about 12 psig. During each operating cycle machine. The components of the unit showed no signs of cracking, pitting, deformation or deterioration under the test conditions. In the ring crush tests, a minimum of pounds was determined with an average of about I059 pounds for the tests. In another series of tests, the

(about min. each specimen was exposed to ultraviolet light from the carbon are for 102 minutes and the ultraviolet light and water for 18 minutes. The test was continued until the samples had been exposed to ultraviolet light for a total of 612 hours and ultraviolet light and water for a total of 108 hours. The samples showed no cracking, crazing, distortion or other signs of deterioration as a result of this exposure.

Hydrostatic pressure tests were also conducted on sample units. The extinguishing unit assemblies (less piston actuator plate and nozzles) was fitted with an adaptor, filled with water and connected to a source of hydrostatic pressure in a manner which excluded all air from the enclosed volume. The pressure was gradually increased at a rate of approximately 300 psi per minute until failure occurred. It was expected that the unit would be able to withstand a minimum of 4 times the average working pressure (4 X 46 184 psi.) without rupture. As a result of these tests, a minimum rupture strength of about 220 pounds per square inch and a minimum of 400 pounds per square inch were measured.

While specific structures and variations of the same have been shown and described herein for purposes of illustration, it is to be understood that various modifications and equivalents of such structures will be apparent to one skilled in the art. Accordingly, the present invention includes such modifications and equivalents and is to be limited only in accordance with the appended Claims.

I claim:

1. An improved fire extinguishing system, comprising; container means; a body of dry, powder-form fire extinguishing agent comprising a metal carbonate selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, alkaline earth metal carbonates, alkaline earth metal bicarbonates and mixtures thereof, in a major amount of about 50 to 95 per cent by weight, and a synthetic metal silicate, in a minor amount of about 50 to 5 percent by weight and sufficient to form an air-impermeable coating on the burning surface to which it is applied and prevent reignition of an extinguished flame for at least l minutes, disposed in said container; expelling means for expelling said extinguishing agent from said container; and a flame-actuated sensor means, resistant to spontaneous ignition at temperatures normally encountered in said area to be protected, operatively connected to said expelling means to actuate said expelling means when a flame contacts said sensor means and said sensor means burns, extending from said container and freely exposed in said area to be protected.

2. A system in accordance with claim 1 wherein the container means is a generally-tubular container.

3. A system in accordance with claim 2 wherein a frangible disc means is mounted in the container in contact with one end of the body of extinguishing agent.

4. A system in accordance with claim 3 wherein a free-floating piston means is mounted in the container in contact with the other end of the body of extinguishing agent.

5. A system in accordance with claim 4 wherein a second frangible disc means is mounted in the container on the side of the piston means opposite the body of extinguishing agent.

6. A system in accordance with claim 5 wherein the expelling means is a pressure-generating means for rupturing the second frangible disc and forcing the piston means through the container whereby the pressurized extinguishing agent ruptures the first frangible disc means.

7. A system in accordance with claim 2 wherein piston means is mounted in the container in contact with one end of the body of extinguishing agent for expelling said extinguishing agent from said container.

8. A system in accordance with claim 7 wherein the expelling means is a pressure-generating means for driving the piston means through the container.

9. A system in accordance with claim 2 wherein the body of extinguishing agent is disposed in the container between a pair of frangible discs.

10. A system in accordance with claim 2 wherein the body of extinguishing agent is packed in the container.

11. A system in accordance with claim 10 wherein the body of extinguishing agent is packed in the container by shaking said container.

12. A system in accordance with claim 10 wherein the body of extinguishing agent is packed in the container by vibrating said container while introducing said extinguishing agent into said container.

13. A system in accordance with claim 2 wherein the discharge end of the generally-tubular container is closed by a deflecting means having a passage in open communication with the interior of said container for deflecting the extinguishing agent in a path perpendicular to the axis of said container.

14. A system in accordance with claim 1 wherein at least one distributing nozzle is mounted on the discharge end of the container.

15. A system in accordance with claim 14 wherein the distributing nozzle includes means for discharging the extinguishing agent therethrough in a vortical pattern.

16. A system in accordance with claim 15 wherein the entrance end of the distributing nozzle is closed except for a plurality of passages, in open communication with the container and the exit end of said nozzle, and said passages are parallel to and offset from radii of said nozzle and inclined downwardly toward the axis of said nozzle.

17. A system in accordance with claim 16 wherein the passages are formed by a plurality of slots formed in the entrance end of the nozzle parallel to and offset from radii of said nozzle and a plug means is mounted in the entrance end of said nozzle, having a generallyconical configuration with its apex toward the exit end of said nozzle, and at least part of the walls of said conical configuration is opposite the interior openings of said slots.

18. A system in accordance with claim 14 wherein the discharge end of the distributing nozzle is movable in a manner to aim said nozzle at a desired point in the area to be protected.

19. A system in accordance with claim 14 wherein the distributing nozzle is mounted on the container by means of a nozzle support head.

20. A system in accordance with claim 19 wherein the nozzle support head is provided with an aperture for the nozzle and the discharge end of said nozzle passes through said aperture.

21. A system in accordance with claim 20 wherein the nozzle support head has a generally-hemispherical projection projecting outwardly, the aperture is formed in said projection and the nozzle has a generallyhemispherical, annular portion formed adjacent its entrance end which conforms to the shape of said projec tion and fits therein.

22. A system in accordance with claim 21 wherein a nozzle retainer means has a generally-hemispherical portion formed on one end, which conforms to the shape of the hemispherical projection of the support head, and a central passage therethrough, which conforms to the outside contour of the discharge end of the nozzle, and is mounted over that end of the nozzle which projects through the aperture of said hemispherical projection.

23. A system in accordance with claim 22 wherein the aperture through the hemispherical projection of the support head is sufficiently large to permit sliding movement of the nozzle and the retainer over a relatively large area of the surface of said projection.

24. A system in accordance with claim 1 wherein the extinguishing agent comprises 85 to 60 percent of the metal carbonate and to 40 percent of the metal silicate.

25. A system in accordance with claim 1 wherein the extinguishing agent comprises 78 to 80 percent of the metal carbonate and i9 to percent of the metal sili cate.

26. A system in accordance with claim 1 wherein the metal carbonate is sodium bicarbonate.

27. A system in accordance with claim 1 wherein the metal silicate is calcium silicate.

28. A system in accordance with claim 27 wherein the calcium silicate is precipitated calcium silicate.

cent.

33. A system in accordance with claim 1 wherein the expelling means is a pressure-generating means.

34. A system in accordance with claim 33 wherein the pressure-generating means is a container of gas under pressure and means for releasing said gas.

35. A system in accordance with claim 34 wherein the gas is CO 36. A system in accordance with claim 34 wherein the means for releasing the gas is a puncturing means for puncturing said container.

37. A system in accordance with claim 36 wherein the puncturing means is a spring-biased arm means carrying a puncturing pin.

38. A system in accordance with claim 37 wherein the arm is normally held, with the spring under tension, by the sensor means.

39. A system in accordance with claim 37 wherein the arm is held, with the spring under tension, by a clip means and said clip means is held in engagement with said arm means by the sensor means.

40. A system in accordance with claim 1 wherein the sensor means is a wire-type fuse.

41. A system in accordance with claim 40 wherein the wire-type fuse contains a noble metal.

42. A system in accordance with claim 41 wherein the noble metal is palladium.

43. A system in accordance with claim 41 wherein the noble metal is platinum.

44. A system in accordance with claim 41 wherein the wire-type fuse contains a major portion of aluminum and a minor portion of a noble metal.

45. A system in accordance with claim 44 wherein the noble metal is palladium.

46. A system in accordance with claim 44 wherein the noble metal is platinum.

47. A system in accordance with claim 1 wherein the metal silicate is a precipitated metal silicate. 

1. AN IMPROVED FIRE EXTINGUISHING SYSTEM, COMPRISING; CONTAINER MEANS; A BODY OF DRY, POWDER-FORM FIRE EXTINGUISHING AGENT COMPRISING A METAL CARBONATE SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL CARBONATES, ALKALI METAL BICARBONATES, ALKALINE EARTH METAL CARBONATES, ALKALINE EARTH METAL BICARBONATES AND MIXTURES THEREOF, IN A MAJOR AMOUNT OF ABOUT 50 TO 95 PERCENT BY WEIGHT, AND A SYNTHETIC METAL SILICATE, IN A MINOR AMOUNT OF ABOUT 50 TO 5 PERCENT BY WEIGHT AND SUFFICIENT TO FORM AN AIR-IMPERMEABLE COATING ON THE BURNING SURFACE TO WHICH IT IS APPLIED AND PREVENT REIGNITION OF AN EXTINGUISHED FLAME FOR AT LEAST 10 MINUTES, DISPOSED IN SAID CONTAINER; EXPELLING MEANS FOR EXPELLING SAID EXTINGUISHING AGENT FROM SAID CONTAINER; AND A FLAME-ACTUATED SENSOR MEANS, RESISTANT TO SPONTANEOUS IGNITION AT TEMPERATURES NOR-
 2. A system in accordance with claim 1 wherein the container means is a generally-tubular container.
 3. A system in accordance with claim 2 wherein a frangible disc means is mounted in the container in contact with one end of the body of extinguishing agent.
 4. A system in accordance with claim 3 wherein a free-floating piston means is mounted in the container in contact with the other end of the body of extinguishing agent.
 5. A system in accordance with claim 4 wherein a second frangible disc means is mounted in the container on the side of the piston means opposite the body of extinguishing agent.
 6. A system in accordance with claim 5 wherein the expelling means is a pressure-generating means for rupturing the second frangible disc and forcing the piston means through the container whereby the pressurized extinguishing agent ruptures the first frangible disc means.
 7. A system in accordAnce with claim 2 wherein piston means is mounted in the container in contact with one end of the body of extinguishing agent for expelling said extinguishing agent from said container.
 8. A system in accordance with claim 7 wherein the expelling means is a pressure-generating means for driving the piston means through the container.
 9. A system in accordance with claim 2 wherein the body of extinguishing agent is disposed in the container between a pair of frangible discs.
 10. A system in accordance with claim 2 wherein the body of extinguishing agent is packed in the container.
 11. A system in accordance with claim 10 wherein the body of extinguishing agent is packed in the container by shaking said container.
 12. A system in accordance with claim 10 wherein the body of extinguishing agent is packed in the container by vibrating said container while introducing said extinguishing agent into said container.
 13. A system in accordance with claim 2 wherein the discharge end of the generally-tubular container is closed by a deflecting means having a passage in open communication with the interior of said container for deflecting the extinguishing agent in a path perpendicular to the axis of said container.
 14. A system in accordance with claim 1 wherein at least one distributing nozzle is mounted on the discharge end of the container.
 15. A system in accordance with claim 14 wherein the distributing nozzle includes means for discharging the extinguishing agent therethrough in a vortical pattern.
 16. A system in accordance with claim 15 wherein the entrance end of the distributing nozzle is closed except for a plurality of passages, in open communication with the container and the exit end of said nozzle, and said passages are parallel to and offset from radii of said nozzle and inclined downwardly toward the axis of said nozzle.
 17. A system in accordance with claim 16 wherein the passages are formed by a plurality of slots formed in the entrance end of the nozzle parallel to and offset from radii of said nozzle and a plug means is mounted in the entrance end of said nozzle, having a generally-conical configuration with its apex toward the exit end of said nozzle, and at least part of the walls of said conical configuration is opposite the interior openings of said slots.
 18. A system in accordance with claim 14 wherein the discharge end of the distributing nozzle is movable in a manner to aim said nozzle at a desired point in the area to be protected.
 19. A system in accordance with claim 14 wherein the distributing nozzle is mounted on the container by means of a nozzle support head.
 20. A system in accordance with claim 19 wherein the nozzle support head is provided with an aperture for the nozzle and the discharge end of said nozzle passes through said aperture.
 21. A system in accordance with claim 20 wherein the nozzle support head has a generally-hemispherical projection projecting outwardly, the aperture is formed in said projection and the nozzle has a generally-hemispherical, annular portion formed adjacent its entrance end which conforms to the shape of said projection and fits therein.
 22. A system in accordance with claim 21 wherein a nozzle retainer means has a generally-hemispherical portion formed on one end, which conforms to the shape of the hemispherical projection of the support head, and a central passage therethrough, which conforms to the outside contour of the discharge end of the nozzle, and is mounted over that end of the nozzle which projects through the aperture of said hemispherical projection.
 23. A system in accordance with claim 22 wherein the aperture through the hemispherical projection of the support head is sufficiently large to permit sliding movement of the nozzle and the retainer over a relatively large area of the surface of said projection.
 24. A system in accordance with claim 1 wherein the extinguishing agent comprises 85 to 60 percent of the metal carbonate and 15 tO 40 percent of the metal silicate.
 25. A system in accordance with claim 1 wherein the extinguishing agent comprises 78 to 80 percent of the metal carbonate and 19 to 20 percent of the metal silicate.
 26. A system in accordance with claim 1 wherein the metal carbonate is sodium bicarbonate.
 27. A system in accordance with claim 1 wherein the metal silicate is calcium silicate.
 28. A system in accordance with claim 27 wherein the calcium silicate is precipitated calcium silicate.
 29. A system in accordance with claim 1 wherein the metal silicate is selected from the group consisting of alkali metal silicates and alkaline earth metal silicates and mixtures thereof.
 30. A system in accordance with claim 1 wherein the fire extinguishing composition contains a small amount, up to about 5 percent, of a desiccant.
 31. A system in accordance with claim 30 wherein the desiccant is calcium stearate.
 32. A system in accordance with claim 30 wherein the desiccant is present in an amount of about 3 percent.
 33. A system in accordance with claim 1 wherein the expelling means is a pressure-generating means.
 34. A system in accordance with claim 33 wherein the pressure-generating means is a container of gas under pressure and means for releasing said gas.
 35. A system in accordance with claim 34 wherein the gas is CO2.
 36. A system in accordance with claim 34 wherein the means for releasing the gas is a puncturing means for puncturing said container.
 37. A system in accordance with claim 36 wherein the puncturing means is a spring-biased arm means carrying a puncturing pin.
 38. A system in accordance with claim 37 wherein the arm is normally held, with the spring under tension, by the sensor means.
 39. A system in accordance with claim 37 wherein the arm is held, with the spring under tension, by a clip means and said clip means is held in engagement with said arm means by the sensor means.
 40. A system in accordance with claim 1 wherein the sensor means is a wire-type fuse.
 41. A system in accordance with claim 40 wherein the wire-type fuse contains a noble metal.
 42. A system in accordance with claim 41 wherein the noble metal is palladium.
 43. A system in accordance with claim 41 wherein the noble metal is platinum.
 44. A system in accordance with claim 41 wherein the wire-type fuse contains a major portion of aluminum and a minor portion of a noble metal.
 45. A system in accordance with claim 44 wherein the noble metal is palladium.
 46. A system in accordance with claim 44 wherein the noble metal is platinum.
 47. A system in accordance with claim 1 wherein the metal silicate is a precipitated metal silicate. 